Treating and impregnation of wood



' which may be extracted by suitable means;

' converted into resins by hydrogenation.

s Au 25, 1936 TREATING Ann nnons'rroiv or'woon Per K. Frolich, Elizabeth, N. .ll., assignor to Standard Oil Development @ompany, a corporation of Delaware No Drawing. Application February Ill, 1932. Serial No. 592,445

oi. (oi. 91-08) This invention relates to an improved. method for the treating and impregnation of wood, fiber obtained on subjecting petroleum oils to decomposition temperatures at elevated pressures.

In the thermal decomposition or cracking of hydrocarbon oils there is usually produced as a residual by-product a dark viscous mass known as cracking coil tar, This tar. contains resins t also contains heavy diflicultly volatile oils which may be used for the production of improved resins. The tar also contains asphaltenes which may be The resins obtained by these and other similar methods may be suitably called synthetic petroleum resins, as they are produced from petroleum oils which, before treatment, contain substantially no resins.

It has now been found that the synthetic petroleum resins obtained from cracking coil tars are especially suitable for use in the treating and impregnation of wood and similar materials. These resins are completely soluble in ordinary hydrocarbon solvents used for wood impregnation and may be used in volatile solvents such as light gasolines or in heavy substantially non-volatile hydrocarbon oils such as those customarily used for the impregnation of wood with high melting waxes. These resins are substantially free from asphaltic matter" or asphaltenes and therefore possess none of the undesirable qualities imparted to ordinary petroleum residues by these substances.

These resins in proper concentration may be used to stain wood a rich color similar topiahogany or oak, the shade depending upon the particular type and concentration of resin and type of wood treated. These resins usually render the surface of wood less slippery and glossy than do ordinary dyes, varnish stains and the like. Wood pregnated at elevated pressure with a solution of these resins contains the resins distributed throughout it so that the impregnated wood may be subsequently cut or planed into any desired shapes without change in the color or finish of the product. Such products are especially suitable for flooring and similar uses where they are subjected to considerable wear since it is impossible to remove the color by abrasion of the surface of the wood. These. resins are remarkably stable, are su nv unsqp njfiable and hence are resistant to the action of saponifying agents which may be used in preparations tor cleaning floors and. the like.

A method of preparing resins by a selective solvent extraction of the residue formed by cracking a non-resin-containing oil after removal of oily components of the residue is described in the co-pending application Ser. No.572,059 filed October 30, 1931, by Stewart C. Fulton. This method is illustrated by the following example:

Example 1.

1000 gallons of cracking coil tar, gravity A. P; I. was distilled under vacuum toa still temperature of 660 F. leaving 1334. pounds of bottoms, softening point 225 F. (ball and ring method) The bottoms were taken up in 508 gallons of kerosene distillate or Varsol in two hot extractions with agitation (391 gallons for first extraction and 127 gallons for extracting the residue). In this way 1000 pounds of the bottoms were found to be soluble in the Varsol leaving 334 pounds of insoluble asphaltenes. 200 pounds of 66 B. sulfuric acid was added to the Varsol' solution with agitation, the agitation being continued for minutes. After settling, the granular sludge was removed by decantation and filtration, and the VarsoPsolution agitated with 80 pounds of Attapulgus fines for 15 minutes. The Varsol solution was then filtered to remove the clay and distilled to separate the .Varsol from the resin yielding 584 pounds of resin, softening point 193 F, (ball and ring method).

A process-for preparing a resin from a vacuum distillate, obtained from cracked tar by treating the tar distillate fractions with chlorine, subsequently removing the chlorine and oily constituents by distillation, and extracting the resin from the distillation residue with a selective solvent, is described in co-pending application Ser. No. 572,058, filed October 30, 1931, by Stewart C. Fulton. This process is illustrated by the following example:

Example 2 1000 pounds of tar distillate from a cracking coil tar (10 A. P. I.) representing the total-overhead boiling up to 660 F}. at 1 mm. pressure, was

chlorinated until the percentage of combined chlorine reached 9.7%. The chlorinated distillate chloric acid. Then the distillate was subjected to a vacuum distillation under reduced pressure until a temperature corresponding to 660 F. at 1 mm. pressure was reached. 208 pounds of high softening point residue (S. P. 282 F. ball and ring method) was obtained in this way, which was extracted with light naphtha leaving an insoluble residue amounting to '75 pounds. After removal of the naphtha by distillation 133 pounds of light colored resin was obtained having a softening point of 188 F. (ball and ring meth- Still another process for obtaining resins from very difiicultly volatile hydrocarbon oils such as those obtained on distillation of cracking coil tar at reduced pressure, which comprises chlorinating the distillate and agitating it with a condensing agent such as aluminum chloride, hydrolyzing the reaction product, separately removing an oily layer, removing oily constituents therefrom by distillation, and extracting a. resin from the residue of this distillation with a selective solvent, is described in the co-pending application Ser. No. 572,060, filed October 30, 1931, by Stewart C. Fulton and John Kunc. This process is illustrated by the following example;

Example 3 1000 pounds of distillate from a cracking coil tar of petroleum origin, boiling between 300 F. and 660 F. under an absolute pressure of 1 mm. mercury, was chlorinated at 80 F., using a cooling system to prevent increase in temperature until the chlorine content became 9.7% by weight.

are produced by the destructive hydrogenation of hydrocarbon oil distillates at elevated temperatures and pressures and have Kauri butanol values generally above 40 or 50. These synthetic petroleum resins are useful both as dyes and resins in the preparation of surface coating compositions. For example, they may be used in admixture with hydroformed solvents and nitrocellulose or other cellulose plastics for the preparation of lacquers.

Such solutions may also be used for impregnating wood in admixture with suitable impregnants such as those ordinarily used for treating wood with high melting waxes, such as Montan wax, petroleum waxes and the like. The wax impregnation of wood is ordinarily conducted at elevated pressures and at temperatures insuflicient to cause charringof the wood, but sufficiently elevated to render the impregnant freely mobile; Petroleum waxes melting above 150 F. and obtained from waxy crudes such as Talang Akar and Pendoepo and heavy waxy distillates containing such waxes are especially suitable for usev in conjunction with these resins for the impregnation of wood. These waxes, or the heavy waxy distillates containing them, may be readily decolorized by suitable petroleum'refining methods such as treating with sulfuric acid, aluminum chloride, clay or bone char and the like and form a suitable medium in which the color of the resin may be used to good advantage. The

use of these petroleum waxes and waxy distillates The chlorinated distillate was pumped into a tank/in wood impregnation is described in the coequipped with an agitator and sealed bya reflux condenser. 50 pounds of anhydrous aluminum chloride was then added and the ure agitated for 12 hours at 80-90 F. After the reaction was complete the reactign I e was washed with water and the oil and sludge charged to a still. The temperature was brought up to 600 F. at atmospheric pressure, then cooled and vacuum applied. The distillation was continued until the temperature of the bottoms became the equivalent of 660 F. under 1 mm. of mercury. In this way 293 pounds of high boiling condensed product was obtained. The bottoms was extracted with 300 gallons of 86 A. P. I. naphtha, obtaining 221 pounds of resin in solution. After removing the solvent by atmospheric distillation there was obtained 221 pounds of resin having a softening point of 213 F.

A process for the preparation of resins by the hydrogenation of asphaltenes remaining after -the removal of resins from cracking coil tars with selective solvents is described in co-pending 'application Ser. No. 572,228, filed October 30) 1931, by Fulton and 'Kalichevsky.

These synthetic resins derived from petroleum aregenerally soluble in hydrocarbon oils such as light naphthas, gasolines, lubricating oils, etc., linseed oil, China wood oil and esters such as amyl acetate and benzol. They are insoluble in water, the lower water soluble alcohols and acetonea They are at least partially compatible with nitrocellulose. Solutions of these resins in suit- .able solvents such as those described above may be used in staining wood and in the preparation of coating compositions generally, such as lacquers, paints, varnishes, and the like. Especially suitable solvents for the preparation of coating compositions containing these resins are the hydroformed solvents described in co-pending application Ser. No. 583,703 filed Dec. 29, 1931, by Robert T. Haslam. These hydroformed solvents pending application Serial No. 588,228 filed Jan. 22, 1932, by Frolich and Baldeschwieler.

The following example illustrates one method of using these synthetic petroleum resins for the impregnation of wood:

Example 4 A slop out having a melting point of F. is obtained as an intermediate fraction between the paraflin distillate and residue on the vacuum distillation of reduced Talang Akar crude. This slop cut is rendered substantially colorless by clay filtration, sulfuric acid treating, or other refining methods. 10 parts of this synthetic peture is complete the bath is allowed to cool slowly to about 150 F. and the pressure is then released to atmospheric. The expanding air in the wood forces out excess treating material. After cooling, the wax and oil adhering to the surface are scraped from the wood. There is obtained by this process a wax-and-oil impregnated wood which will not sweat or become tacky on exposure to sunlight. Other impregnating methods are also suitable as will be understood by anyone familiar with the wood impregnation art.

The. slop cut used in the above example may be prechlorinated by contact with free chlorine asLdescribed in the co-pending application Ser. No. 586,460 filed Jan. 13, 1932 'by' Baldeschwieler and Mudge and by the use of this impregnant a wood is obtained which will not spot or bleach when contacted with water. The wood mayalso impregnated with these synthetic petroleumresins by any 01 the methods shown above. This treatment is of especial advantage in waterproofing and weather-proofing such materials. Various modifications of these impregnating methods will be readily ascertainable, and are considered phaltenes and obtained from a viscous residual tar resulting on cracking a resin-free petroleum oil, said resin being an unsaponifiable solid, clear, light yellow to reddish brown in color, softening point above 80 E, soluble in petroleum naphtha,

linseed. oil and benzol and insoluble in water. lower alcohols and acetone and being obtained from said cracked petroleum tar by means selected from the group consisting of extraction from said tar with a selective solvent, chlorination and subsequent dechlorinationand condensation of distillate from said tar boiling between about 300 and 660 mat one millimeter absolute pressure of mercury, and by hydrogenation of the asphaltenes or said tar.

2. Composition of matter according to claim 1 and containing in addition thereto a normally solid wax in admixture with said resin.

3. Process for the treatment of wood comprise ing impregnating the wood with a stable petroleum resin, consisting substantially of hydrocarbon, in such concentration as to produce a mahogany to oak color, said resin being substantially free of asphaltenes and obtained from a viscous residual tar resulting on cracking a resinfree petroleum oil, saidresin being an unsaponi-- iiable solid, clear, light yellow to reddish brown in color, softening point above 80 F.; soluble in petroleum naphtha, linseed oil and benzol and insoluble in water, lower alcohols and acetone and being obtained from said cracked petroleum tar by means selected from the group consisting of extraction from said tar with a selective solvent, chlorination and subsequent dechlorination and condensation of distillate from said tar boiling between about 300 and 660 F. at one millimeter absolute pressure of mercury, and by hydrogenation of the asphaltenes of said tar.

4. Process according to claim- 3 in which said wood is impregnated with a solution of said resin in a light coloredhydrocarbon solvent.

5. Process according to cla'.im 3 in which said wood is impregnated with a solution of said resin and-a wax melting above about 150 F. in alight colored hydrocarbon solvent.

PER K. FROLICH. 

